Iterate Over String.prototype

I am aware that the for in loop can help iterate through properties of objects, prototypes and collections. The fact is, I need to iterate over String.prototype, and though console

Solution 1:

The specification says:

If the value of an attribute is not explicitly specified by this specification for a named property, the default value defined in Table 7 is used.

Table 7 — Default Attribute Values

...

[[Enumerable]] false

So it is not enumerable (as with all built-in properties).

Solution 2:

Like others have said, all properties in String.prototype are non-enumerable. To get a list of all the properties, including non-enumerable, use Object.getOwnPropertyNames() (newer browsers only)

Solution 3:

Native methods aren't visible through an for(prop in obj) iteration.

It's possible to find properties when you loop through a built-in object. In this case, the page has extended the prototype with a custom method. Frameworks (such as jQuery) often modify built-in objects in this way.